A conventional pet grooming tool with replaceable comb heads as disclosed in Taiwanese Patent No. M370331 generally includes a tubular handle and a plurality of comb heads. Each of the comb heads has a shaft portion detachably coupled with an end of the handle and locked by means of a collar locking device. By operating a shifter to rotate a ring sleeved on the end of the handle, a collar fixed on the handle is unlocked so as to permit removal of the comb head from the handle for replacement of another comb head. Such pet grooming tool has a large number of components, thereby resulting in a higher manufacturing cost and inconvenience during assembly.